Fiberglass shoe for sanding tools

ABSTRACT

A shoe for sanding and rubbing tools is made of laminations of fibre glass of predetermined thickness to provide the right amount of stiffness, flexibility and 100 percent memory. For orbital machines, a vinyl rubbing surface is bonded to the circular shoe with a peripheral edge part forming a tire bonded to the edge of the shoe.

llnited States Patent 1 Rodstein FIBERGLASS SHOE FOR SANDING TOOLSInventor: Harvey B. Rodstein, 6419 Shenandoah, Los Angeles, Calif.

Filed: Sept. 9, 1970 Appl. No.: 70,849

U.S. C1 ..51/358, 51/170 TL, 51/170 MT Int. Cl. ....B23b 23/04, B24d11/02, B24d 15/04 Field of Search ..51/358, 364, 170 T, 51/170 TL, 170MT, 394, 400, 401, 407; 161/93 References Cited UNITED STATES PATENTS8/1960 Welch ..51/378 11 3,732,651 51 May 15, 1973 3,510,992 5/1970Hutchins ..51/358 X 2,606,947 8/1952 Happe ....5l/17O MT X 2,334,17211/1943 Champayne ..51/170 MT 3,082,582 3/1963 Jeske ..51/358 3,533,19310/1970 Dudek ....5l/170 MT 2,561,449 7/1971 Ruderman ..161/93 PrimaryExaminer-Donald G. Kelly Attorney- Herzig & Walsh [57] ABSTRACT A shoefor sanding and rubbing tools is made of laminations of fibre glass ofpredetermined thickness to provide the right amount of stiffness,flexibility and 100 percent memory. For orbital machines, a vinylrubbing surface is bonded to the circular shoe with a peripheral edgepart forming a tire bonded to the edge of the shoe.

2 Claims, 9 Drawing Figures PATENTED 3.732.651

SHEET 2 BF 2 I BY M mu A rrae/vfys I FIBERGLASS SHOE FOR SANDING TOOLSSUMMARY OF THE INVENTION The invention relates to the field of sandingor rubbing tools. Tools of this type are well known, many of them beingpneumatically driven. They are provided with a shoe which may bereciprocated back and forth or moved orbitally; the shoe may berectangular and elongated or circular. In the prior art conventionallythe shoe has been made of aluminum for various reasons. The first isthat the weight must be minimized otherwise the tool as a whole would bemuch too heavy and further the vibration of the tool would be excessive.Typically these tools have been subject to a number of seriousdeficiencies. One of course was that the movement of the shoe occasionedvibration of the tool in use which is a very definite drawback from thestandpoint of use by the human operator. More importantly, however, thealuminum does not have complete memory and when bent will not return toits original position or condition thus destroying its usefulness as ashoe because of loss of its planar condition. In use, tools of thistype, quite often a portion of the working surface of the tool isapplied to the material and considerable pressure may be applied. Thusthis part of the surface may be an end part of an elongatedreciprocating shoe or an edge surface of a circular or orbital shoe. Thepressure will deform an aluminum shoe which will not return to a planarsurface thus effectively destroying its usefulness. Furthermore, it isextremely easy forthese aluminum shoes to become bent or deformed in useas a result of rough handling, dropping or the like.

A further drawback to shoes of the type referred to is that the aluminumshoe necessarily at the edge has a rounded bead or fillet rather than asharp square shoulder. Sanding material which may be paper is attachedto the shoe and because of the edge configuration it cannot extend fullyto the edge because of the rounded bead or fillet. This creates aserious drawback. Often the edge of the shoe may be used for featheringand because of the fact that the paper does not come all the way to theedge this purpose is defeated and furthermore the edge of the papertends to fray, tear and wear out so that it has to be replaced after avery short time.

The herein invention is one that effectively overcomes all of thedrawbacks described. The concept was originated of a shoe which wouldhave 100 percent memory so that upon being bent or deformed it wouldreturn to a true planar condition and further, one that would be aconfiguration such that sanding paper could extend all the way to theedge of the shoe, and further one that would be sufficiently light as toeliminate or reduce vibration to a minimum. A solution to the problemand realization of the concept came about as a result of a search forand discovery of a construction having the desired characteristics andproperties. A shoe having the desired characteristics was realized by aconstruction comprising two laminations of fiberglass material ofdifferent thickness and the laminations being bonded together.Fiberglass is of course a readily available commercial materialavailable in sheets. It was discovered that two laminations bondedtogether, one lamination being in a thickness of 0.0040 inches to 0.0080inches and the other in a thickness of 0.0070 inches to 0.00110 inchesprovided the desired characteristic of stiffness but yet with theability to bend and percent memory in return to a planar condition afterbending. This combination also provided the necessary strength withlightness of weight. Furthermore, this combination provided a shoe whichcould have a square shoulder at the edge making it possible to securethe sanding paper all the way to the edge and typically by adhesive. Itwas found that this combination overcame all the deficiencies of theprior art while at the same time bringing forth a number of bonusadvantages. The pieces of fiberglass are laminated, that is, bondedtogether with epoxy, a particular machine having been designed andconstructed to perform this operation. The machine is a power press withheating resistors installed in place to provide the necessary heat whilelaminating under pressure. The sanding paper is typically glued onto theshoe, that is, attached with adhesive. It has been found that afiberglass shoe of this construction will last a year or more and it isof such construction that it is possible to feather an edge with it.

In the preferred form, a further layer of fiberglass is secured to theshoe by being bonded thereto with overhanging extending side flanges orshoulders to form side guideways to receive guides to provide for thereciprocating movement of the shoe. Thus the entire moving shoeincluding its attachment means to the tool is made of fiberglass thuscontributing to the lightness in weight.

Orbital type tools are at times provided with a disc of rubber orsimilar composition with a rubbing surface. This material in the pasthas been bonded to an aluminum shoe but this gives rise to seriousdeficiencies. When the tool is used in a manner as described in theforegoing the rubber or other composition comes loose ,from the aluminumand readily wears, tears, frays and becomes detached. A construction hasbeen devised to jeliminate these drawbacks. In a preferred form of thisconstruction the rubbing surface is made from a mate- 'ial such as avinyl which is constructed with an edge Lart in the form of a tire so tospeak which is formed pr molded around the edge of the vinyl orfiberglass disc shoe and is bonded thereto.

In the light of the foregoing, the objects of the invention include thefollowing.

The primary object is to reduce the weight of tools of this type, toreduce vibration and to facilitate manual handling.

Another object is to provide a shoe which is flexible and which has 100percent memory and will retain its planar condition.

Another object is to make available a shoe of the type referred to, towhich sanding material can be attached all the way to the edge of theshoe so that the shoe can be used for feathering. A further object is toprovide a shoe formed of fiberglass comprised of laminations offiberglass of particular thicknesses bonded together, whereby to providethe desired characteristics.

Another object is to provide a construction of shoes for orbital typesof tools or sanders, wherein the rubbing surface is covered with vinylhaving an edge part formed as a tire around the edge of the shoe and isbonded thereto.

Further objects and additional advantages of the invention will becomeapparent from the following description and annexed drawings wherein:

FIG. 1 is a perspective view of a tool having the shoe of the inventionembodied therein;

FIG. 2 is a perspective view of the fiberglass laminations from whichthe shoe is formed;

FIG. 3 is an illustrative view, illustrating the process of laminationof the fiberglass layers;

FIG. 4 is a sectional view of an end part of a tool of FIG. 1;

FIG. 5 is a section view taken along the line 5-5 of FIG. 4;

FIG. 6 is a sectional view illustrating utilization of the tool;

FIG. 7 is a perspective view of an orbital type tool having theconstruction of the invention embodied therein;

FIG. 8 is a partial view of the shoe of the tool of FIG. 7; and

FIG. 9 is a sectional view taken along the line 99 of FIG. 8.

The tool shown in FIG. 1 is exemplary of sanding tools of the typeshown, for example, in U. S. Pat. No. 3,563,134 issued on Feb. 16, 1971.Typically tools of this type are pneumatically driven, the details ofthese mechanisms being well-known in the art.

As shown in FIG. 1, the tool comprises a generally elongated body 10,having a tapered front part as shown at 11, and a rear part 12, whichhas flat inset side portions. The tool has a'handle or grip, asdesignated at 14. The back part of the grip is secured to the rear partof the tool body and then extending up and over the rear part of thetool, the front part of the grip being secured to the top of the toolbody, as designated at 18. A further grip or holding knob, as designatedat is attached to and extends upwardly from the forward narrower part ofthe tool body 11.

The shoe is designated generally by numeral 24. It reciprocateslongitudinally with respect to the tool body. As stated, typically thetool may be a pneumatically driven tool, a source of compressed airbeing connected to the tool through tube or pipe 26, which connects tofitting at the back part of the tool.

Suitably secured to the sides of the tool body by rivets, or the like,are side guide plates 32 and 34, which have inwardly extending footportions 36 and 38, which form guides for a guide plate 40. The guideplate 40 reciprocates in the guides. The shoe 24 is attached to theguide plate 40, as will be described.

The fiberglass shoe is of rectangular configuration as designated at 44and is formed of layers or laminations of fiberglass laminated togetheras described in the foregoing.

Numeral 46 designates a layer, which is a pad of cushioning materialwhich may be sponge rubber, or the like, which is adhesively bonded tothe fiberglass shoe. The sanding paper, designated at 50, being securedto the pad 46, by adhesive bonding.

The figures illustrate a preferred form of construction in which theguide plate 40 is also a strip of fiberglass material. Between the shoe44, and the strip 40, is another narrower strip of fiberglass material,as designated at 52. The strip 52 is adhesively bonded to the shoe 44,and the strip 40, that is the guide member, is adhesively bonded to thestrip 52, so that the entire reciprocating assembly other than the padand the sanding paper is constructed of fiberglass.

The shoe assembly as described, can be secured to the reciprocatingdrive mechanism by way of pins such as shown at 56, in FIG. 5. FIGS. 2and 3 illustrate more clearly the construction of the shoe 44. FIG. 2illustrates two layers or laminations of fiberglass as designated at 60and 62. These laminations are commercially available in fiberglass, andthe preferred thicknesses of the two layers are as follows. Lamination60 is preferably in a range of thickness of 0.004 inches to 0.008inches, and lamination 62 preferably has a thickness in the range of0.0070 inches to 0.00110 inches. The laminations are placed together,overlying each other in a Iiminating machine or tool as illustrated inFIG. 3. Appropriate heat and pressure are applied to bond the twolaminations together, the laminations resting on an anvil or a supportbed, as designated at 64 and the pressure being applied by a die 66, sothat the laminations become a single, integral member, which is themember 44.

The resulting product 44 possesses the desired combination ofcharacteristics, particularly as to strength and lightness of weight.The member 44 has 100 percent memory, meaning that it is bent whenpressure is applied to an end or edge, as illustrated in FIG. 6, andafter release of pressure, the shoe will return to its exact planar,original condition. The edges of the shoe 44, provide square shouldersso that the pad 46, and/or the sanding paper can be adhesively bondedall the way to the edge of the shoe.

As will be observed in the shoe assembly, it is made of fiberglass,which can flex as shown in FIG. 4, particularly when pressure is appliedto an edge, as shown in FIG. 6, and the material having 100 percentmemory, will return to its original, planar condition. This is aremarkable advantage compared with metal shoes, particularly consideringthe weight advantage, the tool being one that is manually handled andthe minimization of vibration being critical in importance.

FIGS. 7, 8 and 9 illustrate an adaptation of the invention to an orbitaltype tool. Tools of this type are also well-known in the art. Thesetools also typically being pneumatically driven. In FIG. 7, numeralillustrates generally a typical pneumatically driven tool of this typehaving a generally rectilinear body part 72, and an extending handlepart 74. On the upper side of the handle is a controlling lever 76,which controls the supply of driving air through tube connected to afitting 82 on the handle. At the lower part of the body 72, iscylindrical portion 86 from which extends the shaft 90, which orbits.That is the shaft does not rotate about its own axis, but rather itorbits about a central axis as designated at 92. The stem 90 has an endflange 94, and secured to the stem is the shoe 100. Shoe is made offiberglass and is of the same construction as the shoe 44. Bonded to thecircular shoe 100, is circular fiberglass disc 102. Between the disc 102and the flange 94 is a metal washer 104. The shoe assembly is secured tothe stem 90 by way of a screw 108, having a head 110.

The particular tool illustrated is a rubbing tool. Typically tools ofthis type in the prior art have been provided with a circular aluminumshoe with a disc of rubber adhesively bonded to the shoe to form therubbing surface. As previously described, in use the rubber or othercomposition on such a tool comes loose from the aluminum and readilywears, tears, frays and becomes detached. In the construction of FIGS.7, 8 and 9, numeral 112 designates a disc formed of vinyl of appropriatethickness which may be a few thousandths of an inch or thicker ofperhaps even an eighth of an inch in thickness, which disc is bonded tothe shoe 100. Additionally, the disc 112 is provided with peripheraledge parts as designated at 114, having an inwardly extending angularflange 116 adjacent to an angular slot 118, so that the peripheral edgeengages over the edge of the shoe 100, as shown, and is securely bondedthereto.

The shoe shown in FIGS. 7, 8 and 9 has all of the desirablecharacteristics in connection with the previous embodiment. Further, byreason of the rubbing material 112, being formed as described to ineffect form a tire around the periphery of the shoe 100, thedeficiencies of the prior art constructions are avoided. The vinylmaterial cannot become unbonded or tear loose from the shoe, and is notsimilarlY subject to wearing, tearing and fraying and the fact will lastpractically indefinitely without deterioration.

FIG. 8 illustrates how all edge portions of the shoe can deform or bendand still return to the planar condition with 100 percent memory. Thispermits operations where pressure is applied to an edge of the sandingdisc causing the shoe to bend and to return to normal after the pressureis released. The bonding of the edge of the vinyl material to thesanding disc accomplishes the purposes referred to in the foregoing.

From the foregoing, those skilled in the art will understand the natureand construction of the invention and the manner in which it achievesand realizes all of the purposes and objectives set forth in theforegoing.

The foregoing disclosure is representative of preferred forms of theinvention and is to be interpreted in an illustrative rather than alimiting sense, and the invention to be accorded the full scope of theclaims appended hereto.

I claim:

1. As an article of manufacture, a shoe adapted for use with sanding orrubbing tools, comprising: a member made of fiberglass material ofpredetermined thickness, said member being constructed to havesufficient stiffness for rubbing purposes, but having enough flexibilityto bend when subjected to pressure and possessing characteristics thatafter being bent, it will return fully to its original planar condition,a second fiberglass member forming a slider and means securing saidsecond member to the first member in a manner to provide edge portionsadapted to be guided for longitudinal reciprocating motion.

2. An article as in claim 1, including a third flat fiberglass memberbetween the first and second members,

and the three members being bonded together.

1. As an article of manufacture, a shoe adapted for use with sanding orrubbing tools, comprising: a member made of fiberglass material ofpredetermined thickness, said member being constructed to havesufficient stiffness for rubbing purposes, but having enough flexibilityto bend when subjected to pressure and possessing characteristics thatafter being bent, it will return fully to its original planar condition,a second fiberglass member forming a slider and means securing saidsecond member to the first member in a manner to provide edge portionsadapted to be guided for longitudinal reciprocating motion.
 2. Anarticle as in claim 1, including a third flat fiberglass member betweenthe first and second members, and the three members being bondedtogether.